Sprayed Liquid Flaps: A Numerical Assessment of a Multiphase Jet Concept

Sprayed liquid flap (SLF) is a novel powered-lift concept that utilizes an atomized liquid spray as a jet flap. Similar to a jet flap, SLFs modulate the flow and aerodynamics using a jet expelled on the pressure surface. However, SLFs differ through two mechanisms: 1) the liquid density is two orders of magnitude larger than the ambient air, and 2) the SLF medium has a porous-like character. The present effort explores SLFs using computational fluid dynamics at a state before experiments and therefore relies on benchmarks of underlying physics associated with a liquid-jet in crossflow. The studies evaluate flow rates, SLF positioning, and configurations spanning a range of flow conditions. The present investigation shows that SLFs can provide lift control combined with drag reduction with potential for application in aircraft. Additionally, the present study demonstrates that SLFs operate as a flow control device, not propulsion. Besides two-dimensional analysis, the SLF concept was investigated in three dimensions, which showed good consistency in potential applications despite three-dimensional effects on the SLF. Overall, this effort indicates the clear potential of a novel flow powered-lift control device useful for a range of aerodynamic applications.